Category: Cool stuff

First it was there, then it wasn’t, and now it just may be back again: the first exoplanet directly observed orbiting a normal star, Fomalhaut b, has had quite a ride.

[This post has a bit of detail to it, so here’s the tl;dr version: new analysis shows an object orbiting the star Fomalhaut may actually be a planet, enveloped in a cloud of dust. We can’t for sure it exists, but we can’t say it doesn’t, either! Earlier claims of it not existing may have been premature. Also, at the bottom of this post is a gallery of direct images of exoplanets.]

First a brief history. In 2008, astronomers revealed huge news: they had successfully taken images of planets orbiting other stars. Up until then, the only evidence we had of exoplanets was indirect, either by their tugging on their stars which affects the starlight, or by having them pass between their stars and us, dimming the starlight.

But, along with Gemini telescope pictures of a family of planets orbiting HR 8799, Fomalhaut b was the first planet ever seen directly, as a spark of light in a picture. Here is that historic shot:

It’s Sauron’s eye! [Click to embiggen.]

The object is labeled. It doesn’t look like much, but the important thing to note is that it moved between 2004 and 2006 (see picture below), and it was definitely in both images taken two years apart. That means it wasn’t some bit of noise or detector error. Moreover, the movement was consistent with what you’d expect from a planet. Not only that but the star Fomalhaut is surrounded by a vast ring of dust – Sauron’s eye – and the inner edge of the ring is sharp. That’s what you would expect if a planet was orbiting inside the ring; its gravity sweeps up the dust on the inside of the ring. Given the brightness, we were looking at an object with a few times Jupiter’s mass, much smaller than a star, so definitely a planet.

All in all, it looked good, and it looked real.

Then, in early 2012, some astronomers threw a Pluto-esque wet blanket on the news. A planet that big should be bright in the infrared. Fomalhaut is a youngish star, only a few hundred million years old. Any planet more massive than Jupiter should still be hot, radiating away the heat of its formation. They looked for it in the infrared, and it wasn’t there.

Uh oh.

To make things worse, they found that if you extrapolate the orbit of the supposed planet using its movement, it should cross the ring. That’s bad, because its gravity would disrupt the ring after a few million years tops. The ring is there, so that planet means the planet must not be.

Their conclusion: this object is a clump of dust, a cloud, orbiting the star. That fits the data, and a planet doesn’t. Cue the sad trombone.

Yegads. Look at the storm center; you can see it towering above the cloud deck and feeder bands of the storm. As if that’s not cool enough, that bit of hardware on the left is actually the SpaceX Dragon capsule, berthed to the ISS since October 10. It is expected to undock and return to Earth on Sunday, splashing down in the Pacific ocean at 12:20 PDT.

Looking at this, I’m not sure if I should be awed or terrified. I think I’ll take a little of both.

[Update: Just to be clear, I am not making light of this hurricane. It’s already killed over 20 people in the Caribbean, and I noted how dangerous it is in my earlier post. As I said in a post about Hurricane Isaac: "Pictures of hurricanes from space are amazing. As always, there’s a fascinating dichotomy to pictures like this, a simultaneous ethereal beauty and repellent violence. Hurricanes are magnificent, and terrifying."]

My friend, the geekeriffic Jessica Mills, interviewed me for her blog on Tech Republic (the second part is here). It was a lot of fun talking with her; we wandered over topics like Hubble, Star Trek, science, Doctor Who, black holes, Neil Tyson and Bill Nye, and what I would do if I encountered advanced aliens in a wormhole (answer: self-promotion).

Jessica is amazing. She is a writer, producer, and actress, and was the driving force behind the very funny web series Awkward Embraces (which I wrote about in a post a while back). If you’re a geek – and you are – you should watch it.

She’s also just cool and funny and smart and talented, and you could do a lot worse than follow her on Tumblr and Twitter. Hey. She was a Geek-A-Week, so you know she’s cool.

A little while ago, the interwebz went all twitterpated over the Ohio State University marching band doing a halftime show tribute to gaming. Don’t get me wrong: it was really cool, especially the part starting at 6 minutes in. I was in a marching band for many years (shocker) and I’m amazed at what OSU did.

But somehow that particular show overshadowed the one OSU did on September 15 that was way cooler. And by cooler, I mean geekier.

Last weekend the Orionid meteor shower peaked. To be honest, it’s a rather weak shower, with a max of maybe 25 meteors per hour. I mentioned it on Twitter and other social media, but it’s usually a so-so shower at best so it didn’t seem worth it to plug it much. Even big showers like the Perseids, Leonids, and Geminids can be fairly variable in what you see, so I usually only plug the bigger ones.

Still, the Orionids can be nice if you have dark skies. Mike Lewinski went out to Embudo, NM (along the Rio Grande river) to do some meteor photography and happened to catch a spectacular fireball from the shower. It even left what’s called a persistent train, a trail of ionized, vaporized material that can glow for quite some time. I combined three of his images into one composite to show you the sequence:

On the left is the fireball, in the middle is the glowing train (as well as a second meteor that fell along the nearly same path as the first), and on the right the trail some minutes after the original meteor. He said the train was visible for over half an hour! He also put together a time lapse animation of it:

[Note: You may need to refresh this page to see the embedded video.]

It’s pretty fast, so you might want to run it a few times. Mike also created a second video that’s zoomed in.

I guess the lesson here is that it can’t hurt to go out and observe meteor showers (here’s a site where you can see when the next one is). You might catch something pretty amazing! And even if you don’t, it’s still a night out under the stars, and that’s still one of the best ways you can spend your time.

More art and science are colliding! The Lunar and Planetary Institute is hosting the Humans in Space Youth Art Competition. Kids from anywhere in the world ages 10 – 18 are encouraged to express their feelings about human spaceflight using "…visual, literary, musical and video artwork".

I’m a big supporter of scientific art, and I think this is a great idea. If you’re that age, or know someone who is, let them know! The deadline for submitting the work is midnight U.S. Central Standard Time, November 15, 2012. The website has the details.

Hey, remember that one ton nuclear rover we sent to Mars? Yeah, that. On October 20, it aimed its megaWatt laser at the sand on Mars and blasted it 30 times in rapid succession, carving out a hole about 3 mm across. NASA kindly has provided a before-and-after animation of the damage inflicted on the Red Planet:

Cool, eh? [Click to coherentlightenate.]

Curiosity’s laser is designed not as a weapon against a hapless Marvin, but instead to do actual science. It very rapidly heats the rock (or sand or whatever) to the point where it vaporizes. Material heated like that glows, and in fact glows at very specific colors. By identifying those colors, scientists can determine precisely what the material is composed of. I gave the details in an earlier post when Curiosity zapped its first rock. You should read it, because spectroscopy is cool, and I spent many years doing it.

This sand was chosen to get lasered because it’s made of fine grains that are blown by the wind. Some Martian sand is bigger, some smaller, but it’s all pretty much formed from eroded rocks. But different grains may have different compositions, and be blown around differently. The only way to know is to find out. So Curiosity will be blasting various things as it roves around Gale crater, its home for the next two years.

Curiosity’s real name is Mars Science Laboratory, and it’s useful to keep that in mind. It’s not just some golf cart tooling around the planet; it’s a fully functional science lab, with cameras, spectroscopes, sampling devices, and more. Everything it does is so we can learn more about Mars. What’s the the history of the planet? Why is its geology the way it is? What’s the deal with it used to having water? Where’d it all go?

I think these are questions worth exploring, even if it means blasting tiny holes in the planet to find out.

Image credit: NASA/JPL-Caltech/LANL/CNES/IRAP/LPGN/CNRS. Tip o’ the Illudium Q-36 Explosive Space Modulator to Keri Bean, including the idea for the title.

Our Milky Way galaxy is a sprawling collection of gas, dust, and hundreds of billions of stars, arrayed in a more-or-less flat disk. In the very center of the galaxy – just as in countless other large galaxies like ours – lies a hidden monster: a black hole. And not just any black hole, but one with four million times the Sun’s mass.

It’s called a supermassive black hole for a reason.

Usually, it’s not doing a whole lot except sitting there being black and holey. But sometimes it gets a little snack, and when it does it can let out a cosmic-sized belch. A very, very, very hot belch. Like it did in July 2012:

[Click to schwarzschildenate.]

These images were taken with NASA’s newest X-ray satellite, NuSTAR (more on that in a sec). NuSTAR can detect high-energy X-rays coming from space, and happened to be pointed toward the black hole when it erupted. On the left is an overview of the region near the center of our galaxy. The whitish area is the stuff immediately surrounding the black hole (the pink glow is most likely from a supernova, a star that exploded in centuries past). On the right is a series of three images showing that region getting very bright in X-rays, then fading away: a flare.

OK, so I know what you’re thinking. How can a black hole – famous for gobbling down everything nearby, even light – get bright and emit so much energy?

Basically, it doesn’t. The stuff around it does.

A black hole by itself is dark. But if a gas cloud gets near, very interesting things happen. The gravity from the black hole stretches out the cloud, because the part of the cloud nearer the hole gets pulled by the gravity harder than the part of the cloud farther away. Also, the cloud probably doesn’t just fall straight it; like an orbiting planet around the Sun it has some sideways motion. This means the hole whips it around, pulling out a long tendril which then spirals ever closer to the Point Of No Return.

So some of the stuff may get flung away, but a lot of it falls toward the black hole. As it nears the hole, it forms a flat disk, called an accretion disk. The material in this disk is tortured by unbelievable forces: the inner part of the disk is whirling madly around the black hole, while the outer part is moving more slowly. The gas is literally heated up by friction as the different parts of the disk rub against each other (other forces like magnetism play a role too). The heating can be HUGE: the gas can reach temperatures of hundreds of millions of degrees!

Gas that hot emits X-rays, which is how this flare was seen by NuSTAR. Probably, a smallish cloud found itself too close to the black hole, got torn apart, and flew down into it. As it did it got extremely hot and blasted out X-rays. But when the whole thing was gobbled down, the X-rays stopped… because there was nothing left to emit them.

So maybe saying this was a belch is a bit misleading, since you do that after you eat something. This is more like your food screaming loudly and incoherently and flailing around while you’re actually eating it. Is that better?

This is a pretty cool observation. For one thing, our local big black hole is usually pretty quiet, so even getting a chance to see something like this is pretty nifty. Second, it can tell us what the environment is like near the black hole. And also, it helps us understand what happens right before some unfortunate object takes The Final Plunge. As I mentioned, every big galaxy has a supermassive black hole – ours is actually rather paltry compared to others; the one in the center of the Andromeda Galaxy is probably ten times more massive than ours – so anytime we can observe something going on with ours, we learn more about how they behave in other galaxies, too.

I’m very glad it was! Now we can watch black holes in our galaxy (and others) as they eat and act rudely. Maybe it’s impolite to stare, but c’mon. When one puts on a fun show like this, it would be wrong not to.